Self-centering slide for extension-tables.



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ATTORN EY THE COLUMBIA PLANDGRAPM co., WASHINGTON, n. c.

W. H. NORTHALL. sur cENTEmNG suns FoRExENsioN TABLES.

I l APPLICATION FILED'MAY 2, 1914. 1,175,801 Patented Mar. 14, 1916.

3 SHEETS-SHEET 2.

MUM@ may, INVENTOR l WITNESSES ATTORN EY THE COLUMBIA PLANOGRAPN C0.,WASHXNGTON, D. cA

W. H. NORTHALI.. SELF CENTERlNG SLIDE FoR EXTENSION TABLES.

APPLICATION FILED MAYZ, 1914.

Patented Mar. 14, 1916.

alk.

INVENTOR ILTU L ATTO R N EY narran stares rafrnnfr onerosi.'

WILLIAM I-I. kN'OR'lI-IALL, OF EVANSVIIJL, INDIANA, ASSIGNOR O'FONE-HALFTO i FREDERICK W. GOEDEKE, OF EVANSVILLE, INDIANA.

SELF-CENTERING SLIDE FOR EXTENSIONLTABLES.

Specification of Letters Patent.

Patentedllllar. 14.-, 1916.

.Application filed. May 2, 1914. SeralNo. 835,955.

.a citizen or" the United States, residing at Evansville, in the countyoi' Vanderburg and State of Indiana, have invented a new and usefulSelf-Centering Slide for Extension-Tables, or" which the following is aspecification.

This invention has reference to improvements in slides for extensiontables, and its object is to provide a seltcentering slide ior thepurpose which will at Vall times remain positive in action, and whichwill avoid certain objections to other slides of like character.

In accordance with the present invention each slide comprises twomembers made fast to respective sections of the table, and thesesections are movable lengthwise along an intermediate section carryingintermeshing Agearing in turn engaging respective outer sections, sothat the slide sections will each have the same extent of travel as theother, although the two sections move in opposite directions.

The invention also provides roller supports taking up the major portionof the friction oi' the slide sections, these roller supports inccnjunction with the gearing serving to hold the oppositely movableslide sections against lateral displacement with respect to theintermediate slide section.

The invention also includes locking means, whereby the table either inthe extended or contracted positions, or any intermediate positions, maybe locked against movement of the parts one relative to the other.

rEhe invention will be best understood from a consideration `of the'following detailed description7 taken in connection with theaccompanying` drawings orminga part oi this specification, with thefurther understanding that while the `drawings show a practical form ofthe invention, the latter is not confined to any strict conformity withhe showing ot the drawings, but may be changed and modiiied so long assuch changes and modifications mark no material departure from thesalientl features of the invention.

In the drawings z-Figure 1 is a bottoniL plan view of an extension tableequipped with slides constructed in accordance with the presentinvention. Fig. 2 is a frag- .eentary @betten-Plas. nenni? .the table,Ojf

Fig.. 1 showing the latter extended and provided with intermediateleaves. F ig. 3 is a .bottom plan view of one of the slides drawn on alarger scale than in the preceding figures, and having agear shieldomitted to expose the gearing. Figye is a top plan view of a slide onthe same scale as Fig. 3. Fig. 5k is a side elevation of the structureot Figs. 3 and el. Fig. 6 is a `longitudinal section on the line 6 6 ofFig. l. Fig. 7 is a section on the line 7 7 ot' Fig. 5, but drawn on alarger scale. Fig. 8 is a section on the line 8-8 of Fig. 6, but drawnon a larger scale. Fig. 9 is a fragmentary section oi: a portion of thelatch mechanism. Fig. 10 is a section on the line 10-10 of Fig. 9 withsome parts in elevation. Fig. 11 is a plan view of another form ofslide. Fig. 12 is a side elevation of the structure o'Fig. 11, showingportions rof the table structure in cross section. Fig. 13 is alongitudinal vertical section of the slide of Fig. 11. Fig. 14 is asection on the line 14-14 of Fig. 11. Fig. 15 is a section onl the line15-15 of Fig. 12.

Referring to the drawings, there is shown a channel strip 1 usuallyconstructed yoi pressed steel, but not necessarily made of suchmaterial, and this strip has a connecting wall 2, while the side membersof the channel terminate at the long edges remote from the wall 2 inoutstanding lianges 3, 4, respectively. The vchannel member is made fastto crossed bars 56 on av pedestal 56a.

On opposite sides of the channel member 1 are slitte members 5 and 6,respectively, each in the form of a plate with a longitudinal centralrib or bead 7 or 8, as the case 'may be. this bead serving to impartstiffness to the slide member. The member 5 has one long edge returnedupon itself in spaced relation to the body of the member and to thatface remote from the bead 7 to form a U-shaped inturned flange 9, andthe member 6 has a similar iange 10. The other long edge of the member 5is returned upon itself in like manner as the flange 9 to form a channelportion 11 with the inner long edge of the channel portion outturned ina direction substantially perpendicular to the channel portion 11 toform a flange `12 which, when the parts are assembled, extends along theconnecting wall 2 of the channel member 1, the flange 12 being incl'osesrelaton to the ,Wall A2 without-undue frictional contacttherewith. The slide member 6 has a return portion 13 similar to theflange 12 of the member 5, and this portion terminates in an outstandingflange 11 similar to the flange 12, and when'the parts are assembled theflanges 12 and 11 are in close edge to edge relation.

The slide member 5 is provided from one end toward the middle portionwith a series of outstanding ears 15, and the slide member 6 has asimilar series of ears 1G but located at the opposite end of the slidemember 6 from the ears 15 of the slide member 5. These ears are designedfor the passage of fastening devices 17, such as screws, for securingthe slide member 5 to one section 1S of a tabletop 19, and the otherslide member 6 tothe other section 20 of the table top.

Extending throughout somewhat more than half the length of the flange 12is a series of'perforations 21 therethrough, while the flange 14 has asimilar `series of perforations 22, but extending from the opposite endof' the slide member G from the series of Aperforations 21 of the flangeof the slide member 5. These series of perforations are of suflicientlength so that when the corresponding ends of the slide members 5 and Gcoincide, the series of perforations 21 overlap the series ofperforations 22 at the central portion of the slide as a whole, all asshown in Fig. 4. F or convenience of description, the ends of the seriesof perforations 21 and 22 at the corresponding ends of the slide memberswill be termed the outer ends of the series of perforations, while thosewhich are brought into overlapping relation will be termed the innerends of the Vside walls of the chamber member 1 are pins 23 suitablysecured at the ends as by riveting. orrotherwise, and'these pins aredistributed at suitable intervals along the length of the intermediatechannel member 1. In the particular showing of' the drawings four suchpins'are indicated. but it will be understood that a greater number maybe provided. One end of each pin is continued through the respectivewall of the channel member. and there carries a disk-like roller 24 or25, as the case may be. Two of the rollers, say the rollers 24, arelodged in the slide member 5 near one end thereof. and the other tworollers 25 are lodged in the slide member G near the other end thereof.rThe rollers 24 and 25 each have a dished hub portion 26 through whichthe respective pin 23 extends, the pin being headed, as at 27, orotherwise formed to support the roller. Thefdislied portion 26 serves tooffset the roller from the respective side ot the channel member 1 toallow for the thickness of the flanges 9 and 10 and the channel edges 11and-13 of the slide members 5 and.- A

keeping them out of such contact as would produce undue friction, and,moreover, holding the members in proper substantially parallel relation.The channel member 1 with the rollers 24 and 25 operates as a spacer forthe slide members 5 and 6 Vand constrain them to parallelism ofmovement.

Extending between the side walls ofthe channel member 1 and at the endssecured thereto, is a series of pins 30, and mounted on these pins is aseries 'of gear wheels 31, 32, 33, 31, and 35, the gear wheels 33 and 34being mounted upon the same pin 30, and are secured together forsimultaneous rotation in any suitable manner. The gear wheels 31, 32 and33 are inv mesh one with the other, and the gear wheels 31 and 35 are inmesh one with the other and are displaced laterally with respect to thefirstnamed group of gear wheels. Since the gear wheels 33'and 34 areconnected for simultaneous movement. there is provided a train ofgearing including the gear-wheels 31, 35, so that movements of the gearwheel -31 are transmitted to the gear wheel 35,

and vice versa. rPhe end-gear wheels 31 and 35 of' the series are sosituated as to engage in the notches 22 and 21, respectively. The othergear wheels serve as transmission and idler gear wheels between the endwheels 31 and 35, and are so arranged that the end wheels 31 and 35rotate inopposite directions. The series of perforatiors 21 and 22operate as racks, so

that when one of the slide members` say the slide member 6, is moved tothe left, as shown by the arrow thereon in F ig. 4, the gear wheel 31 isrotated, and this motion is transmitted to the gear wheel 35. so thatthe latterrotates in the opposite direction,

thus by engagement in the rack made up.

of the series of notches 21 the slide member 5 is propelled toward theright, as viewed'in Fig. 4, the direction being indicated by an arrow onthe slide member 5. Under these circumstances the channel member 1 Vdoesnot move in either direction, but simply maintains its relation to bothmembers 5 and 6. The slide therein becomes automatically self centering.so that the table top members move equal distances from or toward thecentral position. and this relation is alwavs constant due to thepositive connection formed bv the train of gearing, and which connectionis not subject to any changes which might occur from stretching or otherdisplacements where the connections are not of such a positive nature asin the present structure. The terminal gear wheels 31 and 35 extendthrough respective slots 36 in the connecting wall 2. In order to coverthe gearing against Contact which might cause injury, a shield 37 isprovided, and is made fast to the flanges of the channel member 1.

It is desirable to lock the table top sections in different positions ofadjustment, so that they may not be accidentally separated when onceadjusted, and for this purpose a rod 38 is provided, this rod having oneend formed with an angle extension 39, and adjacent such end slidablelongitudinally in a bracket 40 carried by one of the members 5 or 6, theparticular showing of the drawings indicatingthat the rod 38 is carriedby the member 6. The end 39 of the rod 38 is located at some convenientpoint of manipulation, and is of a length to extend toward the other endof the member 6 where the rod is made fast by a pin 41 or otherwise to aslide plate 42, and adjacent to the rod 38 the plate 42 is provided witha longitudinal slot 43 through which there extends a pin 44 fast to theslide member 6. rlhe plate 42 is suitably bent so as to be spaced fromthe corresponding face of the slide member 6 for a portion of the lengthof the plate, and between said plate and the slide member 6 there islodged a latch member 45 having one end formed into a tooth 46, and theother end mounted on a pin 47 carried by the slide member 6. The latchnear its tooth end 6 carries a pin 48 projecting through an inclinedslot 49 in the plate 42, and said plate is also provided with alongitudinal slot 50 traversed by the pin 47. Carried by said pin 47 isone end of a spring 51, the other end of this spring engaging the pin48. Both of the pins 44 and 47 are headed so as to hold the plate 42against the slide member 6, but permitting the longitudinal movement ofthe plate 42.

At appropriate points along the flange 3 of the channel member 1 thelatter is completely punched out to form a series ot teeth 52, therebeing usually as many different series of teeth 52 as there arepositions to which it is desired to adjust the table. top. For instance,in Fig. 2 the table top is shown as containing three leaves 53 and itsuch number of leaves represents the eX- treme extension of the tabletop, then there are provided four series of teeth 52, one seriesrepresenting` the closed position of the table top, and the other threeseries representing positions for one, two or three leaves. By arrangingthe teeth 52 in series, provision is made for different Wdtbsbfzinsertleaves as may be .desired- The rod 38 is constrained toward onelimit of its travel by a spring 54 surrounding the rod and abutting itat one end against the bracket 40 and at the other end against a pin 55extended through the rod. Under the normal action of the spring 54 theplate 42 is moved toward one limit of its travel, and the inclined slot49 is so arranged that at such limit of its travel the tooth 46 is movedinto engagement with one of the teeth 52. |These teeth are inclined, sothat the table top may be readily moved toward the closed position, andwill lock automatically at the proper point during such movement, but ifit be desired to ei;- tend the table, then the manipulating end 39 mustbe actuated to move the rod 38 against the normal action of the spring54, thereby causing the walls of the inclined slot 49 to act on the pin48 to move the latch 45 in a direction to carry the nose 46 out of thepath of the teeth 52, whereupon the table may be extended as far asdesired. On the release of the rod 38, the spring 54 propels it to itsnormal position, thus allowing the latch 45 to move with its nose 46 inengagement with the teeth 52, the spring 51 causing such movement of thelatch under the conditions named.

The strip 28 is arranged in the path of one of the rollers 24, so thatthe slide members 5 and 6 cannot extend beyond a point determined by theengagement of the strip 28 with the nearer roller 24, since the twoslide members are permanently connected through the gearing.

Each slide is composed of an intermediate member and two ianling memberscarrying the intermediate member by means of roller supports, so thatthe outside or Hanking members move with great ease, and are the onesattached to the table top, while the intermediate member has no positiveconnection at all with the table top aside from that provided bv theiianking members. The racks formed on the anking members are of the opentype preventing clogging by anv accumulations. Moreover, theintermediate member forms the sole support for the connecting gearing,causing the ianking side members to move with equal speed in oppositedirections, and also causing such movement to be positive. The flankingmembers also serve as inclosing means for all the moving parts, so thatthese parts are protected against access and any possibility of harm topersons manipulating the table, and avoiding any danger of entangling`anything into the moving parts.

In the structure described the self-centering means comprises twoassociated racks in overlapping relation when the table is in a closedposition and the racks extending on opposite sides of the center pointof the table. ,u .When the vtable top Y sections. are en tended the twonormally overlapping members of the self-centering means move lengthwiseof each other but in opposite directions, being caused to movesimultaneously, though oppositely, at equal speeds by theinterconnecting gearing, which latter engages the racks on respectivelyopposite sides of the center point of the table, with the terminalmembers of the train of Vgearing constituting the gears which engage theracks spaced apart for a considerable distance. This spacing in theparticular showing of Ythe draivings is measured by the combined widthsof tvvo intermeshing idler gear wheels which mesh together in about thecross-central line of the table. With a round topA pedestal table thelength of the self-centering interconnections and the length of aself-centering slide is limited and hence the extension of such aself-centering device or of such a slide is likewise limited, especiallyif the self-centering means be such that the racks when extended stilloverlap at their inner ends. By the interposition of the longitudinallyextended train ofgearing the inner ends of the racks may both overrunthe lateral center line ot the table to respectively opposite sides ofthe latter and the travel of the runners or racks may be correspondinglyenlarged. Because ot this it is quite possible to extend a round toppedestal table to double its closed diameter, or even more. With such anarrangement if the central member and the runners of a slide be all ofequal length and consequently coinciding at the ends in the closedposition, each runner may be extended beyond the corresponding end ofthe middle member which serves as a support to an extent representingmore than half the length o1E the runner and consequently the extendedslide may be more than tivim the length ot the contracted slide, suchslide including self-centering mechanism.

In Figs. 11 to 15 a modified form of the slide is shown, and since inmany respects the parts are similar the same reference numerals areemployed except that they are supplied with the exponent a In Fig. 11and associated figures there is sh own a channel strip 1a having aconnecting Wall 2CL and terminating at the llong edges remote from the.vall 2a in outstanding flanges 3, 4-, re spectively. Slide members orrunners 5a and 6a are provided, each having a longitudinal central rib7a or 8n as the case may be. The member 5a has an inturned U-shapedflange 9a and the member 6a has a similar flange 10, While the otheredges o'f these members have respective inturned flanges 1la and 13a.The slide members or runners 5'L1 and 6a have ears 15'LL and 16 forattachment to the separable parts of a table top. The slide members orrunners 5a and 6a are supported by. thek intermediate member la` throughroll-v ers 24a and 25a which may correspond to the rollers 24 and 25 ofthe structure ot Fig. 1 and associated gures, and these rollers areshown as provided with dished portions 26a land mounted on pins 23carried by the intermediate member la.

The structure of Fig. 11 is shown as applied to cross bars 56 such asare usually carried by the top of the post of a pedestal extensiontable. Under such conditions the ends of the member 1a are each providedwith a perforation through the connecting Wall 2a for a bolt 57extending through the respective bar 56and struck in from the side wallsof the member 1 are ears 58 having matching perforations through whichVthe bolt 57 extends. In order to hold the member 1 to the bars 56, andalso relieve the bolts 57 of undue strain, each flange 3a and 4a isformed With a struck out tooth 59 near the ears 58, this tooth beinglocated to enter the respective bar 56, and thus in conjunction with thebolt 57 anchor the corresponding end of the slide member l.

instead of the gearing connections shown and described With reference tothe structure of Fig. 1 and associated figures, aself-centeringinterconnection of a somewhat diferent type is employed inthe structure of Fig. 11 and associated figures. Mounted in the interiorof the channel member 1a near the ends thereof are flanged rollers G0.being supported upon journal pins G1 carried by the side portions of thechannel member la. Each roller has a portion extending through a passage62 in the connection porticn 2a so as to enter the space betiveen theinturned edges 11a and 13@l of the runners 5a and 6a. One runner, say,the runner 5, has a bracket 63 fast Vthereto near the lovver edge, Whilethe corresponding portion of the side oi the channel member 1 is cutaway for a greater portion of the length of the side memberl asindicated at (34 to admit oi the travel of the bracket 63 therealong,this bracket entering the interior of the channel member la; Made fastto the inturned edge 13a oic the runner 6a so as to project over the topoi" the channel member 121 is a bracket 65, the brackets 63 and 65being` in the same vertical plane as the rollers 60. A chain G6, whichmay be either a tivo part chain or an endless chain, is made fast to thetwo brackets 63 and 6' so that even if the chain be of two parts it isin effect an endless chain. lVhen the parts are in the contracted orclosed position as and 65 are at the limit ot their travel in onedirection and are located near that end of the slide from which therunners move away in the extension of the slide. The rollers GO are ineffect direction-changing rollers, and when one runner is pulled out itacts upon the chain 66 through the respective brackets -63 Orand-thischain in turnacts vshown in Figs. 11. 12 and 13, the brackets G3 uponthe other runner to project it to a like extent, since it is connectedthereto by the other bracket G5 or 63 as the case may be. The action ofthe structure of Fig. ll and associated figures is the same as that ofFig. l and associated figures, so far as the simultaneous and centeringmovements are concerned and needs no further description.

In each embodiment of' the invention illustrated in the drawings thedirection-changing means is elongated in the direction of the length ofthe slide and engages the respective flanking members, when the slide isclosed, at points spaced apart in the direction of the length of theslide. Also, the direction-changing devices are in the main of lessWidth than and located within the space defined by the sides of thecentral or intermediate member, While those portions of the fiankingmembers or runners where connected to the direction-changing meansoverhang or underride the intermediate or central member, so that evenin a structure such as shown in Figs. ll, l2 and 13 Where a iexiblestrand in the form of a chain is shown, such chain rides upon or issupported by the intermediate member and cannot Sag or fall into aposition Where it is liable to jam during the operation of the slide.

slide to be extended to any desired length and then locking it in theadjusted positions against further extension is structurally different,but operatively the same as inv the arrangement shown in Fig. 1 andassociated figures. There is provided a latch dog 45a having a nose 4Garranged to engage series of teeth 52a. The latch dog is urged to thelatching position by a spring 51a. The dog is mounted on a pivot pin47a, but is provided vvith an angle arm G7, and this latch deg beingmounted on the outer face of the respective runner, such runner beingthe runner Ga in the showing of the drawings, the arm 67 is carriedthrough matching slots GS in the rib 8a. At the free end of' the arm GTit is pivotally attached to to one end of a reach rod 38a, While theother end of this rod is connected to one end of a manipulating lever 69extending through matching slots 70 in the rib 8a, the lever beingconveniently situated for manipulation. The operation oi the latch isthe same as described with reference to the other figures of drawing,and hence no detailed description is herein necessary.

What is claimed is 1. A table slide comprising a central or intermediatemember and flanking runners carried by and movable along theintermediate member on opposite sides thereof and in opposite directionsone to the other, andconnecting gearing for the vrunners comprislngvracksy on the respective runnersl and. a

The latch mechanism for permitting the series of connected anddirection-changing gears carried by the intermediate member within thelatter, said series of gears being elongated in the direction of thelength of the slide.

2. A table slide comprising a central or intermediate member havingspaced rollers journaled thereto on opposite sides near respectivelyopposite ends, runners carried by the rollers on opposite sides of thecentral member and movable in opposite directions one to the other,racks carried by the runners in overriding relation to the centralmember, and in longitudinally overlapping relation one to the other whenthe slide is closed.y and a series of connected directionchanging gearscarried by the intermediate member and extended lengthwise thereofiviththe terminal gears of the series on respectively opposite sides ofthe mid point yof the intermediate member and each meshing with thatrespective rack movable to- Ward the same end of the slide when beingprojected. whereby a slide with two runners of equal length to theintermediate member may be extended to or more than double the lengthof' the closed slide.

3. A table slide comprising an elongated channel member with anelongated series of' connected direction-changing gears mounted therein,and flanking elongated runners on opposite sides of the intermediatemember and each provided with a rack in engagement ivit-h respectiveterminal members of the series of gears` the intermediate member beingprovided with rollers on opposite sides near opposite ends and theflanking members having enacting parts embracing the rollers for holdingthe iianking members to the intermediate member and permittingoppositely directed longitudinal movements of the flanking members.

4. A table slide comprising an elongated sheet metal intermediatechannel member with rollers on opposite sides near respectively oppositeends, elongated sheet metal Hanking members or runners each havingopposite edges inturned in embracing relation to the rollers and eachformed with a rack in overriding relation to the intermediate member,and an elongated series of gears mounted in the intermediate member Withthe terminal members of the series of gears laterally displaced and inengagement with the rack portions of the respective runners.

5. A table slide comprising an elongated sheet metal intermediatechannel member with rollers on opposite sides near respectively oppositeends, elongated sheet metal flanking members or runners each havingopposite edges inturned in embracing relation to the rollers and eachformed With a rack inl overriding relation to the intermediatemember,and an elongated series of ners, said racks being arranged side by sideand lapping lengthwise of the slide to anV extent corresponding to theelongation of the series of gears.

6. A table slide comprising an elongated intermediate member with aseries of connected direction-changing gears mounted between the sidesand intermediate of the length of said member and elongated lengthwiseof said intermediate member, rollers carried by the intermediate memberon opposite sides thereof adjacent to correspondingly opposite ends, andslide members or runners mounted on and carried by the rollers formovement longitudinally of the intermediate member and held to saidintermediate member by the rollers, said runners p lengthwise thereofwith the lapped parts engaged by respectively opposite ends of theseries of connected gears 7. A table slide comprising an elongatedintermediate lmember with a series of connected direction-changing gearsmounted intermediate of the length of said member, and said series beingelongated lengthwise of the intermediate member, rollers carried by theintermediate member on opposite sides thereof adjacent tocorrespondingly opposite ends, and slide members or runners mounted onand carried by the rollers for movement longitudinally of theintermediate member and held to said intermediate member by the rollers,said runners being provided with rack portions overriding theintermediate member and lapping lengthwise thereof with the lapped partsengaged by respectively opposite ends of the series of connected gears,the intermediate member and the runners being formed of sheet metal andthe connected series of gears being housed in the intermediate member.

8. A table slide comprising an intermediate member of channel form withrollers mounted on opposite sides near opposite ends, and with aconnected series of direction-changing gears mounted in the channelmember, and flanking slide members having inturned long edges inembracing relation to respective ones of the rollers, and withoverlapping rack portions engaged by the terminal ones of the connectedgears, said flanking slide members having means for attachment torespective sections of a table top.

9. A table slide comprising an intermediate member of channel form withrollers mounted on opposite sides near opposite 55, ends, and with aconnected series of direction-changing gears mounted in the channelmember,and flanking slide members having' inturned long edges inembracing relation to" fianlring slide members having means forattachment to respective sections of a table tcp,rsaid channel memberhaving an outstanding flange with series of latch means thereon, and oneof the flanking slide membei's being provided with latch means movableinto coactive relation with any one of the series of latch means on theintermediatemember. l

l0. In a table slide, an elongated intermediate member having alongitudinal ange with a series of groups of closely associated latchmeans thereon, runners on opposite sides of and carried by theintermediate member, interconnecting means between the runners andcarried by the intermediate member to cause simultaneous movement of the'runners in opposite directions, and a latch member cn and movable withone of the runners into operative relation to any one of the latch meansof any group thereof on the flange of the intermediate member. Y

ll. In a table top slide, an intermediate member provided with alongitudinal flange having series of teeth formed therein interconnectedslide members on opposite sides of the intermediate member, and latchmeans carried by one of the interconnected slide members, said latch,Vmeans comprising a toothed latch having a normal constraint to engagethe teeth on the intermediate meinber, and an actuating means for thelatch for moving it against its normal constraint comprisingv a slidableplate with pin and slot connections with the latch for causing the latchto approach or move away from the teeth in accordance with the directionof movement of the slide, and actuating means for the slide having amanipulating portion.-

12. A table slide provided with an elongated intermediate member,oppositely movable slide members on opposite sides of-said intermediatemember, means carried by the intermediate member for engaging the slidemembers, and the latter having coacting means for causing the positivemovement of the slides in opposite directions, and latch means on one ofthe side members comprising a spring-actuated manipulatingrod, aslidable plate connected thereto and secured to the slide membercarrying it, said plate having an inclined slot, and a. pivoted latchmember with a pin movable in the slot, and with a spring constrainingthe latch member in one direction, the intermediate member beingprovided with a flange portion having series of teeth thereon in thepath of the latch member. v

13. A table slide comprising an elongatedl ala Y With the terminal gearsrotatable in opposite directions, rollers carried by the channel memberon opposite sides near opposite ends thereof, and flanking slide memberscarried by the rollers and each having inturned long edges embracing therollers, and with one long edge formed into a ange having an elongatedseries of perforations constituting a rack and engaged by a respectiveone of the terminal gears of the series.

14.-. A table slide comprising an elongated channel member, an elongatedseries of connected gears mounted in the channel member with theterminal gears rotatable in opposite directions, rollers carried by thechannel member on opposite sides near 0Q- posite ends thereof, andflanking slide members carried by the rollers and each having inturnedlong edges embracing the rollers, and with one long edge formed into aflange having an elongated series of perforations constituting a rackand engaged by a respective one of the terminal gears of the series,each of the flanking members having means for attachment to a respectivemember of a table top.

l5. A table slide comprising an intermediate sheet metal channel member,flanking runners connected to and carried by the intermediate member andeach formed with a flange overriding the with said flange in turn formedinto an cnlongated rack longitudinally lapping the rack portion of thecorresponding iange of the other runner, and an elongated connectedseries of gears mounted in the intermediate member ivitli the terminalgears of the series laterally offset with respect one to the other andin mesh with respective rack portions of the slide members.

16. A table slide comprising an intermediate member, flanking slidemembers or runners connected to the intermediate member for simultaneouslongitudinal movement therealong in opposite directions, each runnerbeing` provided with an elongated flange portion directed toward that ofthe other member and said flanges being arranged side by side and eachprovided with a longitudinal series of perforations lapping at one endthe respective other end of the series of perforations of the otherflange, and an elongated connected series of gears located Within theintermediate member and having the terminal members of the seriesrotatable in opposite directions and Copies of this patent intermediatememberA may be obtained for :tive cents each,

laterally offset to respectively opposite sides of the longitudinalcenter line of the intermediate member and in mesh with the lappingportions of the respective series of perforations.

17. A table slide comprising a central or intermediate channel memberand flanking runners movable therealong in opposite directions one tothe other, and directionchanging means mounted in the channel member andacting on the runners to move them simultaneously in oppositedirections.

18. A table slide comprising a central or intermediate channel member,runners mounted on the channel member on opposite sides thereof andmovable therealong in opposite directions one to the other, anddirection-changing means carried by and in part lodged in the channelmember and having portions exterior to the channel member in position toengage and act upon the runners to move them simultaneously in oppositedirections.

19. A table slide comprising a central or intermediate member, flankingrunners movable therealong in opposite directions one to the other, andself-centering interconnections comprising rack bars on the respectiverunners and movable therewith with the rack bars in longitudinallyoverlapping relation when the slide is closed, and an elongated seriesof interconnected gears carried by the intermediate member and extendingto opposite sides of the mid point thereof `with the terminalgearsengaging the rack bars on correspondingly opposite sides of thesaid mid point, whereby the racks have a. range of extension to overridesaid mid point at their inner ends.

20. A self-centering mechanism for extension tables comprising tivoelongated racks simultaneously movable longitudinally of each other inopposite directions and an intermediately located elongated series ofintermeshing gears having the terminal members of the gears spaced apartand engaging respective ones of the racks, whereby the inner ends of theracks may overrun in opposite directions the mid point of the train ofgears.

ln testimony, that l claim the foregoing as my oivn, 1 have heretoaffixed my signature in the presence of witnesses.

VLLLAM H. NORTHALL.

Witnesses Louis O. Rasen, LOUISE Davis, ALMA E. MEYER.

by addressing the Commissioner of Patents,

Washington, D. C.

